Green switch power supply with standby function and its IC

ABSTRACT

A switch power supply with standby function is disclosed. The power supply can satisfy the need of the green environment protection. And a single ended green switch power supply IC or thick film or modular circuit design with standby function is disclosed, too. It comprises a standby power supply, a main power supply, a PFC device, and a supplemental circuit, wherein a remote control signal is transmitted to main control circuit in response to a main error signal to control main power supply. A method for preventing switch power current from overload and saturation is disclosed too. Finally, the present invention also provides a green power supply with standby function as well as its IC associated with digital processing highly qualified PFC, and a PC standard (such as ATX, ATX12, SSI) computer switch power supply.

BACKGROUND OF THE PRESENT INVENTION

1. Field of Invention

The present invention relates to switch power supply, more particularly,relates to a green (environmentally friendly) switch power supply withstandby function, the switch power supply comprises a standby powersource, a main power source having a remote control, a PFC (power factorcorrection) device, and an supplementary circuit, wherein a monolithicgreen on/off power supply integrated circuit or thick film circuit, ormodular circuit are applied, and the main power is controlled by aremote signal in response to an error signal, and finally, the presentinvention also provides a PC standard (ATX, ATX12, and SSI) for thepower supply.

2. Description of Related Arts

Switching power converters are used in a wide variety of applications toconvert electrical power from one form to another form. For example,DC/DC converters are used to convert DC power provided at one voltagelevel to DC power at another voltage level and AC-DC converters areemployed to convert alternate current power into direct current power.At the same time, switching power converter could be categorized intoisolated or non-isolated power converter, and the basic circuit of theconverter can be configured to step up (boost), step down (buck), orinvert type, even CCM (continuous conduction mode) or DCM (discontinuousconduction mode).

The isolated power converter could be further classified into singleended mode (including forward and flyback converter) and double endedmode (push-pull, half bridge and full bridge converter); the convertingtechnique comprises hard-switched converters and soft-switchedconverters, and the controlling techniques comprise PFM (Pulse FrequencyModulation) mode control, PWM (Pulse Width Modulation), current modecontrol, voltage mode control and so on.

Regardless what methods or mode are used, a switching power circuitgenerally comprises a converter circuit having a power tube, atransformer, an inductance, and at least one rectifying filter outputcircuit, wherein the quantity of the power tube is subject to the choiceof power converter mode, commonly, single ended converter comprises apower tube, the double ended converter comprises a plurality of powertubes. In case of the soft switch is applied, at least one moresupplemental power tube is necessary. The inductance here is being usedfor the simple non-isolated DC/DC converter, while the choice of thechosen converter will simultaneously determine whether the inductance,single-ended or double-ended mode, hard switching or soft switching, tobe applied in practice.

Further, the switching power circuit comprises a feedback circuit havinga sample circuit, an error amplifier, and occasionally a feedbackisolating circuit, wherein the sample circuit is adapted for samplingthe current and voltage signal from the output circuit, and sending thesampled current and voltage signal to the error amplifier to obtain acomparative value, afterwards, the error amplifier will output an errorsignal.

Additionally, the switching power circuit comprises a control circuitincluding an adjustable pulse circuit and a drive circuit, wherein theadjustable pulse circuit having PFM (pulse frequency modulation) mode,PWM mode and so on. According to the error signal, the adjustable pulsecircuit is capable generating a basic pulse, for double-ended mode,there is a scaling-down complementary double pulse circuit, for softswitching multi-pulse circuit, there is a multi pulse circuit. Commonly,basic pulse, double pulse and multi-pulse are supposed to be directedinto the driven circuit. It is noted that a bigger error signal willresult to a larger duty cycle ratio, as well as a higher peak value ofthe power tube current and a saturation susceptible transformer.

Finally, the switching power circuit also comprises an supplementalcircuit which is selected from a group consisting of initiating circuit,protective circuit, voltage reference circuit, EMC circuit, andalternate rectifying filter circuit, wherein the protective circuitcould be further classified into the lower voltage protective circuit,high voltage protective circuit and upper limit current protectivecircuit. Whenever the switch power supply is initiated or overloaded,the transformer and induction is susceptible to be saturated, and powertube is apt to be loaded with over current. So within the art, the powerswitching IC employs the upper limit protective circuit for protection,that is to say, when the current reach the upper limit, the power tubewill be automatically shut off. Therefore, it is required that thecontrol circuit to be promptly responsible and the power tube beequipped with instantaneously shutting-off function. Otherwise, thereexist some sort of hidden risks for the power tube and transformer. Forthe initiating circuit, there are resistance initiating circuit andswitch-off constant current source initiating circuit available withinthe art.

The single end converter circuit could be categorized into single endedforward converter circuit and single ended flyback converter circuit,wherein the single ended forward converter circuit comprises amagnetically reset circuit which is suitable for a powerful switchingpower supply.

PFC (Power Factor Correction) could be classified into the single phasePFC and three phases PFC, CCM (Continuous Current Mode) PFC, DCM(Discontinuous Current Mode) PFC, boost PFC, boost/buck PFC converter,and flyback PFC converter. Further, there are constant frequencycontrolling techniques, constant conduction time controlling technique,and equal area control techniques associated with the DCM mode. Andthere are peak value current controlling technique, average currentcontrolling technique, lag loop current controlling technique, hardswitch and soft switch technique associated with the CCM mode.

Regardless what kinds of converter and switching circuits are beingused, a PFC device generally comprises a converter circuit having apower tube, a transformer, an induction, and an output circuit. In caseof a soft switch is applied, at least one supplemental power tube and asoft switch circuit are employed. And in case of flyback converting modeis used, a transformer would be necessary.

The PFC device further comprises a feedback circuit having a samplecircuit, an error amplifier wherein the sample circuit is adapted forsampling the current signal from the output circuit and then sending thesampled current signal to the error amplifier to generate an errorsignal.

The PFC further comprises a control circuit including an adjustablepulse circuit and a driven circuit, wherein the error signal is send tothe adjustable pulse circuit and the driven circuit is adapted fordriving the power tube. It is noted that there is a variety ofadjustable pulse circuits available depending which kind of convertercircuits and the controlling techniques being used. Commonly, the mostused control circuits include constant conduction time control circuit(for example, UC3852, after the power tube is conducted, the inductioncurrent will be increased and the conduction time will be determined bythe error signal outputted by the error amplifier, after the power tubeis shut off, the induction current will be decreased; if the inductioncurrent is fallen down to zero, the power tube will be conducted againindicating that the circuit is performing at a transition point betweenDCM and CCM). Some popular control circuits also include average timecontrol circuit (for example, UC3854 comprising a multiplicator, ancurrent error amplifier, PWM, and an oscillator), flyback convertercontrol circuit, soft switching control circuit, and so on.

Finally, the PFC device also comprises a supplemental circuit which isselected from a group consisting of initiating circuit, protectivecircuit, voltage reference circuit, EMC circuit, alternate rectifyingfilter circuit. To prevent the PFC outputting voltage being excess theupper limit, designers within the art have to balance the followingfactors, such as the outputting capacity of the capacitor, powerfactors, and total harmonic distortion. In other words, users have tosacrifice some factors to achieve a feedback function. For instance,when the circuit is under a heavy load, the power factor will be reducedand the total harmonic distortion will be accordingly increased.However, sacrifice could solve all troubles, in case of the outputtingvoltage excesses the design value, or the outputting is converted from aheavy load to a light load suddenly, the control circuit sometimes isunaware or unable to judge whether the outputting voltage being over theupper limit. This is due to some inherent factors of voltage errorfeedback and input voltage filter waves. As a result, there still existpotential risks in conventional PFC circuits.

A green switch power supply comprises a standby power supply and a mainpower supply, wherein the standby power supply refers to power-frequencytransformer rectifying standby power supply adapted for outputting avoltage range from a couple of watts to a tens of watts. Preferably, thepower consumption should be lower under a load-free circumstance. For agreen switch power supply adapted for outputting a higher power, a PFCdevice and EMC circuits are necessary. According to the prior art, thestandby power supply and the main power supply are separately designed.At the same time, people have been devoted enormous enthusiasm onto thedesign of the standby power supply and the single power supply. There isno applications or designs concerning too much about the green switchpower supply, i.e. a combined design for reducing the overall costs. Forstandby power supply, a common approach is to provide a linear regulatedpower supply, which is not environmentally friendly. A better approachis to provide an independent standby switching power supply, forexample, IC switching power supply of TOP series. But this kind of powersupply is so expensive.

For the main power supply, there is no special main power IC availablein the market. So nowadays, according to the devices and techniquesavailable on the market, the green switch power supply are either soexpensive or non-applicable.

SUMMARY OF THE PRESENT INVENTION

A primary object of the present invention is to provide a green switchpower supply, which is environment friendly and cost effective.

Another object of the present invention is to provide a green switchpower supply, which is able to overcome the above mentioned drawbacks ofprior art.

Another object of the present invention is to provide a green switchpower supply, a green switch power supply IC, and a PC standard (e.g.ATX, ATX12, SSI) switch power supply.

Accordingly, to achieve the above object, the present invention providesa green switch power supply, comprising:

a standby power supply;

a main power supply;

a PFC device; and

a supplemental circuit;

wherein the main power supply is subjected to a remote signal to beon/off, the standby power supply is adapted for at least supplying anecessary power to the main power supply, the DC input terminal of themain supply power and the DC input terminal of the standby power supplybeing shared with a common ground;

The standby power supply comprises a standby converter circuit, astandby feedback circuit, a standby feedback circuit, a standby controlcircuit and a standby supplemental circuit, wherein the standby controlcircuit and DC input terminal of the standby power supply being sharedwith a common ground. The standby power supply is embodied as a RCCswitching power supply or a power transformer DC power supply.

The main power supply comprises a main converter circuit, a mainfeedback circuit, a main control circuit and a main supplementalcircuit, wherein the main control circuit and the main power supply DCinput share a common ground.

The supplemental circuit is selected from a group consisting of power-oninitiating circuit, AC rectifying filter circuit, voltage referencecircuit, EMC (Electromagnetic Compatibility) circuit.

The PFC device comprises a PFC converter circuit, a PFC feedbackcircuit, a PFC control circuit, and a PFC supplemental circuit.Alternatively, a passive PFC device could be applied. It is noted atleast an output of the PFC device is embodied as a DC input of mainpower supply.

The standby converter circuit of the standby power supply comprises astandby power tube, a standby transformer, and at least one standbyrectifying output circuit. From a cost perspective, the standbyconverter circuit commonly employs the single ended flyback convertercircuit. In case of a great power is required, the standby controlcircuit could employ the single ended forward converter circuit orsingle ended hybrid converter circuit, the power tube is directly drivenby the standby control circuit, so that the soft switching convertercircuit and the double ended converter circuit are eliminated from theoptions.

The standby feedback circuit could be embodied as an isolated standbyfeedback circuit or a non-isolated standby feedback circuit, wherein theisolated standby feedback circuit comprises a standby sample circuit, astandby error amplifier, a standby isolation circuit (commonly anoptically coupled isolator is used in applications), wherein the standbysample circuit is adapted for sampling a voltage signal and then sendingthe sampled voltage signal to the standby error amplifier to generate astandby optically coupled current, and finally to output an standbyerror signal via the standby isolation circuit. It is worth to mentionthat the weaker the standby optically coupled current signal is, thebigger the standby error signal would be.

The standby non-isolated feedback circuit comprises a standby samplecircuit, a standby error amplifier wherein the standby sample circuitcollects the signal which is applied as the voltage signal of thestandby control circuit for the standby power supply and proportionallymatched with the standby output voltage signal after the filtration bythe standby transformer winding. After then, the collected signal willbe send to the standby error amplifier to output error signal. It isunderstood that the standby non-isolated feedback circuit is suitablefor being used to output non-accuracy voltage, and for being used in acost effective way.

The standby control circuit comprises a standby pulse adjustable circuitand a standby driven circuit, wherein the standby pulse adjustablecircuit is adapted for generating a standby pulse in response to thestandby error signal. If the standby converter circuit is embodied as asingle ended standby converter circuit, the standby pulse will bedirectly send into the standby driven circuit, and the standby drivencircuit is adapted for driving the standby power tube. The standby pulseadjustable circuit could be classified into PFM mode, PWM mode as wellas other modes. The PFM mode refers to the standby pulse frequencyadjustable circuit and standby pulse width shaping circuit, and the PWMrefers to the standby pulse width adjustable circuit and standbyoscillator.

Finally, the standby supplemental circuit is selected from a groupconsisting of standby protective circuit, standby voltage monitorcircuit and so on.

The main converter circuit of the main power supply comprises a mainpower tube, a main transformer, at least a main rectifying filter outputcircuit. To save the cost, the single ended main converter circuit isapplied and the main power tube is directly driven by the main controlcircuit, in case of a converting efficiency is required, a single endedsoft switch main converter circuit could be desirable.

The main feedback circuit is embodied as a main isolation feedbackcircuit comprising a main sample circuit, a main error amplifier, a mainisolation circuit (commonly isolated by optically couple), a remotecontrol circuit, wherein the main sample circuit is adapted for samplinga voltage output signal and then sending the sampled voltage outputsignal to the main error amplifier to generate a main optically coupledcurrent. Afterwards, the optically coupled current will output a mainerror signal via the main isolation circuit. It is noted that theoptical coupling is applied in the remote control circuit for sendingremote control signal to the main control circuit.

The main control circuit comprises a main pulse adjustable circuit, amain driven circuit, and a main power prohibitive circuit. In case ofthe remote control signal is off, the main power prohibitive circuitwill force the main driven circuit to output a lower electrical level toshut off the main power tube, otherwise, the main pulse adjustablecircuit would generate a main pulse in response to the main errorsignal. If the single ended main converter circuit is applied, the mainpulse will be directly send to the main driven circuit, and then themain driven circuit will normally drive the main power tube. It is notedthat the main pulse adjustable circuit could be embodied as PFM mode,PWM mode and so on. For PFM mode, a main pulse frequency adjustablecircuit or a main pulse width shaping circuit could be possible, for PWMmode, a main pulse width adjustable circuit and a main oscillator are ofoptions. The main supplemental circuit is selected from a groupconsisting of main protective circuit, main voltage monitoring circuit.

The PFC converter circuit of the PFC device comprises a PFC power tube,a PFC transformer or a PFC induction, at least a PFC output circuit,wherein the PFC transformer is flyback mode if the flyback converter isbeing applied. The PFC feedback circuit comprises a PFC sample circuit,a PFC error amplifier wherein the PFC sample circuit is adapted forsampling a voltage signal from the PFC output circuit, and then sendingthe sampled voltage signal to the PFC error amplifier to output a PFCerror signal. The PFC control circuit comprises a PFC pulse adjustablecircuit and a PFC driven circuit wherein the PFC error signal is send tothe PFC pulse adjustable circuit and the PFC driven circuit is adaptedfor driving the PFC power tube. The PFC supplemental circuit is selectedfrom a group consisting of PFC initiating circuit, PFC protectivecircuit and AC rectifying circuit.

The operation of the main power supply is subject to the remote controlsignal. That is to say, according to the main error signal, the remotecontrol signal is capable of enabling the main control circuit tooperate the main power supply. There is a working power supplyassociated with the main control circuit. If there is no working powersupply associated with the main feedback circuit, the main error signalshould be less than a threshold value (commonly, the minimum value). Asa result, when the remote control signal is off, the main error signalis forced to be less than the threshold value or the minimum value. Whenthe remote control signal is on, there is no effect impact on the mainerror signal. In case of the main error signal is less than thresholdvalue, the remote control value is assumed to be off and the main powersupply will be shut off by the main control circuit. It is noted thatthe threshold value is selected from the minimum value of the main errorsignal (commonly 0) to a maximum value of the main error signal(commonly 100%). Generally, the threshold value is a fraction of themaximum value. When the threshold value is optimally chosen, the mainpower supply is easily to be set On and Off thus improving the overallefficiency. For example, if the threshold value is 25%, and the load ofthe main power supply is less than 25%, the main power supply is apt tobe working cyclically.

Therefore, the above mentioned main power supply circuit has beenconverted to an isolated circuit associated with a built-in remotecontrol circuit, wherein the isolated circuit is capable of forcing themain error signal to be less than the threshold value (for instance,forcedly adjusting the voltage signal of the main output, or forcedlyadjusting the main optically coupled current, or directly cutting offthe working power supply of the main feedback circuit) if the remotecontrol signal is off. However, if the remote control signal is on, theremote control circuit will be neutralized to out of function. At thesame time, the main sample circuit will sample the voltage signal fromthe main output, and subsequently send to the main error amplifier togenerate a main optically coupled current and ultimately outputting amain error signal via the main isolation circuit. Preferably, when thevoltage signal of the main output has a bigger value than the presetvalue, the main optical couple is current free, and the main errorsignal is minimized. Otherwise, a bigger derivation of the main outputvoltage signal would result to a bigger main optical coupled current,and finally cause a higher main error signal.

The main power supply prohibitive circuit is adapted for monitoring themain error signal of the main feedback circuit. If the main error signalhas a value less than the threshold value, the remote control signal isconsidered to be Off, thus forcing the main pulse adjustable circuitstop outputting pulse and forcing the main driven circuit outputting alower electrical level, or even other procedures to shut off the mainpower supply. Otherwise, according to the main error signal, the mainpulse adjustable circuit would output a main pulse, and the main drivencircuit would normally drive the main power tube (commonly, the singleended power tube is driven by DC); to ensure that the main feedbackcircuit not associated with a working power supply has a main errorsignal valued less than the threshold value, a resistance or a constantcurrent source could be applied in the main control circuit to pull downthe inputted main error signal.

The green switch power supply according to the first preferredembodiment of the present invention further comprises a green switchpower supply IC having a standby control circuit, a main control circuitand a supplemental circuit. The supplemental circuit comprises apedestal generator, an initiating circuit, and an offset circuit whereinthe pedestal generator is adapted for providing a reference voltage tothe internal circuit, the initiating circuit is adapted for creating aninitiating working condition for internal circuit and the offset circuitis adapted for establishing an offset for the internal circuit. Whilethe standby pulse adjustable circuit and the main pulse adjustablecircuit both employ the PWM mode and apply the same working frequency,the standby pulse adjustable circuit and the main pulse adjustablecircuit could share the PWM oscillator thus further reducing the costs.

Furthermore, the green switch power supply IC comprises a PFC erroramplifier, a PFC control circuit, a sample circuit for sampling theworking voltage of the IC and a standby error amplifier. Commonly, agreen switch power supply being equipped with the IC of the presentinvention is supplied by a standby power supply, so that the internalfeedback circuit will limit the maximum working voltage of the IC. It isnoted that the standby feedback isolated circuit and the internalstandby feedback circuit are being used simultaneously, wherein theinternal feedback is adapted for limiting the outputting voltage. As aresult, the IC of the present invention is suitable for being used for alower voltage output accuracy thus saving the costs of such green switchpower supply.

Furthermore, the remote control signal which is correspondingly matedwith the main error signal is feed into the main control circuit,wherein a main power supply IC is utilized for integrating the maincontrol circuit.

The green switch power supply according to the preferred embodiment ofthe present invention could be a kind of thick film circuit comprising astandby control circuit, a standby feedback circuit, a main controlcircuit, a main feedback circuit. Preferably, the thick film circuitcomprises a PFC feedback circuit and a PFC control circuit.

The green switch power supply according to the preferred embodiment ofthe present invention could be a kind of modular circuit comprising astandby control circuit, a standby feedback circuit, a main controlcircuit, a main feedback circuit. Preferably, the thick film circuitcomprises a PFC feedback circuit and a PFC control circuit.

The present invention further provides a PC standard (for example ATX,ATX12, SSI and so on) green computer power supply, comprising a standbypower supply, a main power supply wherein a standby converter circuit ofthe standby power supply is embodied as a single ended convertercircuit, and a main converter circuit of the main power supply isembodied as a single ended forward converter circuit or a single endedhybrid converter circuit. Furthermore, the above mentioned green switchpower supply comprises PFC devices.

The present invention further introduces a kind of single ended hybridswitch power supply converter circuit, wherein at least one path isadapted for single ended forward outputting, and at least another pathis adapted for single ended flyback outputting, any single path ofsingle ended forward outputting is able to be common-channeled withcertain path of single ended flyback outputting.

In other words, the single ended forward pulse current is outputted, andthe exciting current is arranged not back to the DC input terminal(winding magnetic resetting), but bleed to the output terminal of theswitch power supply through the secondary winding. It is noted that thesecondary winding is independent secondary winding or share with otherforward windings. Since the energy of the exciting current is designedless than the energy of the forward conversion, so that one outputtingterminal having higher power outputting rate could be chosen foroutputting the exciting current. So in the later design for the singleended hybrid converter circuit, the effective magnetic resetting of theinputting terminal could be less than the permissible DC input voltage,therefore, the number of windings could be reduced. As a result, theswitch power tube's voltage withstanding capabilities have beensignificantly improved, a wider range of inputting voltage could beaccepted, and finally the manufacturing process of the switchtransformer could be simplified.

The present invention further provides a method for preventing currentoverloading and saturation of a switch power supply, comprising:

1) checking whether a primary current of an transformer, a current of aninduction and a current of a power tube being excess an upper limitcurrent;

2) generating an adjusting signal directly or indirectly adjusting anerror signal if the upper limit current is excess the upper limit, sothat during subsequent adjustable periods, a duty cycle is reduced, theprimary current or the induction current or power tube peak currentvalue are reduced, wherein the error signal is outputting signal from anerror amplifier or is inputting signal from a pulse adjustable circuit,the error adjustable signal is a direct error adjustable signal, theindirect adjusting signal is an inputting signal from an error amplifieror an outputting signal from a sample adjustable circuit to adjust theerror signal.

In the step 2), if an over-limit current was detected, the error signalwould be adjusted, and the adjusting capacity is a fixed value.

The step 2) further comprises a step for continuously adjusting theerror signal during the subsequent adjustable periods if an over-limitcurrent is detected, wherein the adjusting capacity is an graduallydecreased value, from a maximum value to 0; It is noted that during thesubsequent adjustable periods, in case of the upper limit current isexcess again, the adjusting procedure will be restarted graduallydecreasing from the maximum value to 0.

The present invention further provides an overloading and saturationpreventative switch power supply according to the above mentionedprocedure, comprising:

a converter circuit comprising a power tube, a transformer (or aninduction), at least a path of rectifying filter outputting circuit, andsometimes a soft switch circuit;

a feedback circuit comprising a sample circuit, an error amplifier, andsometimes a feedback isolation circuit;

a control circuit comprising a pulse adjustable circuit and a drivencircuit, where the pulse adjustable circuit is selected from a groupconsisting of PFM mode, PWM mode and so on; and

a supplemental circuit.

wherein a protective circuit of the supplemental circuit comprises aserial of transformer primary or power tube current sample circuit, aserial of transformer primary or inductance or power tube upper limitcurrent detecting circuit, and a regulating circuit adapted for directlyand indirectly regulating the error signal according the outputtedsignal from the detecting circuit, wherein the regulating circuit is a Dflip-flop being downward edge triggered and high electrical levelpreset. The clock signal of the D flip-flop is the pulse adjustablesignal of the control circuit. In response to the error signal from thefeedback circuit, the pulse adjustable signal generate a basic pulse,and the data terminal of the D flip-flop will be feed into with a lowelectrical level. And the preset input terminal of the D flip-flop willbe feed into the outputted signal from the detecting circuit. If the Dflip-flop is under a high electrical level, the open circuit will outputa error regulating signal. Therefore, whenever an over limit current isdetected, the regulating circuit will automatically regulate the errorsignal. It is noted that the regulating volume is a fixed value.

According to the present invention, the converter circuit of the switchpower supply is single ended converter circuit, and the power tube istriode, the driven circuit comprise at least two path of output signal,one path is coupled with the base of the triode, and the other path iscoupled with the emitter of the triode. The base of the triode iselectrically connected with a high voltage power source via a highlyresistible resistance. Associated with related circuits, the highlyresistible resistance and triode of the converter could be applied as aportion of the power on initiating circuit, so as to improve thewithstanding of the triode.

The switch power supply of the present invention utilizes a singleswitch power supply IC which at least integrates a portion of controlcircuit and protective circuit.

The present invention further provides a digital process and highquality PFC (power factor correction) method, wherein a referencecircuit and a PFC reference signal are applied for replacing theconventional feedback circuit and error signal. The reference circuitcomprises a series of voltage signal sample circuit of the outputcircuit, voltage signal detection or module converter (A/D) circuit,reference logic circuit and reference output circuit. the referencelogic circuit is adapted for digitally processing the voltage signal soas to generate a digital reference signal, and for regulating thereference signal at a plurality of preset cycle point, wherein duringeach cycle, the reference signal is kept constant. The cycle is integermultiple of the commercial power, and each ending point of the cycle issynchronized with the edge of the commercial power half cycle. In otherwords, the cycle is much larger than the half cycle of the commercialpower.

The present invention further provides a PFC device based on the abovedigital process and high quality PFC method, which comprises a convertercircuit having power tube, a transformer or an inductance, an outputcircuit, a reference circuit, a control circuit having a pulseadjustable circuit and a driven circuit wherein the reference is feedinto the pulse adjustable circuit for controlling a generation of apulse, and a supplemental circuit selected from a group consisting ofinitiating circuit, protective circuit, voltage reference circuit, EMCcircuit and so on.

According to the present invention, the pulse adjustable circuitcomprises a ratio current circuit, a timing circuit, a pulse widthadjustable logic circuit, a current amplifier and an oscillator whereinthe PFC reference signal is applied as the output of the ratio currentcircuit, a pair of digital signal of the timing circuit are send to thepulse width adjustable logic circuit which in turn is adapted foroutputting a pair of digital signal to the timing circuit, the outputsignal of the current amplifier is send to the timing circuit, theoutput signal from the oscillator is send to the pulse width adjustablelogic circuit, finally the pulse width adjustable logic circuit willoutput a pulse signal. The different portion of the pulse widthadjustable logic circuit will be discussed in details later.

The PFC device of the present invention utilizes power factor to correctIC which comprises a portion of reference circuit and control circuit.

Finally, the present invention also provides a optimal technique versionfor the green switch power supply IC, the standby power supply is singleended flyback mode or single ended hybrid mode, PWM mode is applied, thestandby power tube is directly driven by the standby driven circuit, theoverload and saturation preventive design is fulfilled, the main powersupply is singled ended flyback or hybrid mode, and of PWM mode, sharesa PWM oscillator with the standby power supply, the main power tube isdirectly driven by the main driven circuit, the remote control signal,with response to the error signal, is adapted for controlling the mainpower supply on/off, and an overload and saturation preventive design isfulfilled. The PFC device is embodied as a digital process and highquality PFC method.

Conclusively, the green switch power supply equipped with the monolithicgreen switch power supply IC design not only simplifies the circuit, butalso reduce the overall costs significantly. In short, the applicationof thick film and modular circuit make the power supply more reliableand facilitate the maintainability process. The remote control designcould further reduce the costs and prevent any accidental operation.What is more, the single ended forward converter has been replacedsingle ended hybrid mode converter, so that the voltage withstanding ofthe power tube has been improved. Finally, the overload and saturationpreventative and digital processing PFC method further enhance thequality of the power supply. The above mentioned techniques could beused as PC standard (ATX, ATX12, SSI) so as to efficiently reduce thecosts and improve the power supply quality and reliability.

These and other objectives, features, and advantages of the presentinvention will become apparent from the following detailed description,the accompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an undefined PWM switch power supplyhaving an initiating circuit to prevent overload and saturation.

FIG. 2 is a schematic diagram showing an alternative mode of anunqualified PWM switch power supply having an initiating circuit toprevent overload and saturation.

FIG. 3 is a schematic diagram of an overload and saturation preventativeundefined PWM switch power supply according to the preferred embodimentof the present invention.

FIG. 4 is a schematic diagram of an undefined digital process and highquality PFC according to the preferred embodiment of the presentinvention.

FIG. 5 is a schematic diagram showing an alternative mode of anundefined digital process and high quality PFC according to thepreferred embodiment of the present invention.

FIG. 6 is a schematic diagram showing a simplified digital process andhigh quality PFC according to the preferred embodiment of the presentinvention.

FIG. 7 is a schematic diagram of a green switch power supply accordingto the preferred embodiment of the present invention.

FIG. 8 is a schematic diagram of an alternative mode of a green switchpower supply according to the preferred embodiment of the presentinvention.

FIG. 9 is a schematic diagram of an alternative mode of a green switchpower supply according to the preferred embodiment of the presentinvention.

FIG. 10 is a schematic diagram showing a PC ATX standard green switchpower supply being used in application.

FIG. 11 is a schematic diagram showing another mode of PC ATX standardgreen switch power supply being used in application.

FIG. 12 is a schematic diagram showing a PC ATX standard green switchpower supply being used in application according to the preferredembodiment of the present invention.

FIG. 13 is a schematic diagram showing a single ended hybrid switchpower supply.

FIG. 14 is a schematic diagram showing a single ended hybrid switchpower supply.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1 and FIG. 2, the independently used switch powersupply, for example a charger, a green switch power supply IC standbypower supply unit, or a universal switch power supply is illustrated. Q1is an economical power bi-polar transistor; Qd is a power tube such as apower MOSFET or a an insulated gate bi-polar transistor; the regioncircumscribed within the dash line is IC portion. It is noted that Rband Qa could integrated in the IC portion or apart with the IC portionaccording to the semiconductor manufacturing process. Furthermore, Rbcould be integrated within the IC portion according to the optimizingrequest of a lower power output. In case of a higher output power isneeded, the Rb could be coupled with an external resistor in a parallelmanner for outputting a bigger power.

As shown in FIG. 3, a main power supply adapted for being used as agreen switch power supply is illustrated. The region circumscribed bythe dash line is IC portion, the power tube Q2 could be eitherintegrated in the IC portion or disposed outside the IC portion. Ia andIb are current source. Accordingly, Q2 and Qd are power tubes which arepower MOSFET, or IGBT (insulated gate bipolar transistor).

S0 is a Schmidt comparator. The working condition of the IC power supplyvoltage monitoring circuit is subject to the condition of the S0. Thatis to say, if the S0 is in a lower level, the IC power supply voltagemonitoring circuit is set in an initiating state, instead, if the S0 isin a high level, the IC power supply voltage monitoring circuit is setin a normal state.

As shown in FIG. 1, the IC power supply voltage monitoring circuit isset in an initiating state, QC terminal of a trigger device PCL(hereafter called PCL.QC) is set as high resistance (or output iscontrollable), the high-voltage high-resistance value R1 provides a basemicro-current enabling the power tube Q1 to be conductible under a lowercollected current, and to be charging the IC power supply capacitor C0through diode Da to form an initiating circuit. To ensure that Q1 couldbe safely initiated, the following procedures could be followed, such aschecking the charging current, controlling the PCL.QC outputting,altering Q1 base current, and enabling the Q1 current to be safe value.While the IC power supply voltage monitoring circuit is set in a normalstate, PCL.QC and Qa is outputting normally, R1 is disabled. Therefore,if the Q1's amplifying function is considered, and compared with theresistance limited current initiating circuit, the initiating circuitunder a normal state will be reduced to a less extent.

As shown in FIG. 2, under an initiating state, capacitor C0 is chargedby high voltage high current power supply to form PWMs initiatingcircuit; under a normal state, PWMs is resumed to be a normal state, andthe high voltage current power supply is cut off. As shown in FIG. 3,since the main power supply and the standby power supply share IC powersupply voltage monitoring circuit, so that S0 is effective towards PWM2,under the initiating state, PWM2 is cut off.

As shown in FIG. 1, under a normal state, the output from PCL.QC and Qterminal of the trigger device PCL (hereafter call PCL.Q) is the same.For example, if the output is high electrical level, Q1 and Qa isconductible, Rb is adapted to check the instantaneous current of Q1; ifthe high level output converts to a lower level, Qa will be cut off, dueto the fact of memory effect, Q1 will not cut off immediately, and diodeDa will be fly-wheel, or a time delay circuit is designed to delay Qa'off until Q1 is cut off, or Qa force emission terminal of Q1 clamping tobe a value 1.5V, as a result, the base voltage of Q1 0V will be reversebias so as to increase the withstand voltage of the collector of Q1.

As shown in FIG. 2, under a normal state, if Q terminal of triggerdevice PCLs (hereafter called PCLs.Q) outputs a high electrical level,Qd will be conductible, Rb is adapted for checking the instantaneouscurrent of Qd; if the output is a lower electrical level, Qd will be cutoff. As shown in FIG. 3, under a normal state, if Q terminal of triggerdevice PCL 2 (hereafter called PCL2.Q) outputs a high electrical level,Q2 is conductible, R2 is adapted for checking the instantaneous currentof Q2; if the output is low level, Q2 is cut off.

S2 and PWM comparator shares a same mechanism, that is, as long as theoscillator Q arisen, the power tube is conductible, the primary currentof the transformer will be increased as well as the voltage drop. Whenthe voltage drop equal to or bigger than the error signal which arerepresented as voltage UC1 or UC2, S2 will output a lower electricallevel and the power tube will be cut off; However, the maximum cycleration is determined by the oscillator, that is to say, if the outputfrom the S2 is high level, oscillator Q will convert to a lower leveland the power tube will be cut off; here, the schmiter comparator S1could be embodied as a main power supply prohibitive circuit. if theerror signal has a value less than the threshold value, then the powertube cycle will be forcedly cut off, instead, if the error signal valuehigher than the threshold value, the power tube cycle will be turned on,so as to increase the conversion efficiency while the switch powersupply is light loaded.

The upper limit current comparator S3 could be embodied as an upperlimit current checking circuit. In case of the primary transformer orpower tube reach the upper limit current, S3 is capable of enabling theoverloading and saturation preventative logic S5 and simultaneously turnoff the power tube. There are several methods available, according tothe present invention, S5 is enabled only once, and S4 is adapted forconducting an oscillator cycle if the following circumstance issatisfied. The current of S4, namely I4, should be bigger current thanthe current source Ia or the main voltage feedback current minus currentsource Ib. (as shown in FIG. 3, the difference value is Ic). It is notedthat I4, Ia and Ic have attributed to the UC1 and UC2 within a singlePWM cycle are ranged within 2.8V*(−10%), while the maximum currentoutput should be above 95%. In case of the assignment from Ia towardsUC1 is 2.8V*3.3%, I4 could be selected three or four times bigger thanIa. As a result, the error signal will be weakened, so in the next PWMcycle or the following PWM cycle, the duty cycle will be decreased andthe primary current of the transformer and the peak current of powertube will be decreased as well.

For those quick power tubes, transformers having bigger capacities, andquick responding control circuit, the error signal will be located closeto the maximum value if overloading. For those slow power tubes,transformers having limited capacities (once the transformer issaturated, the primary current will increase to excess the upper limit),or retarded response control circuit, the error signal will be less thanthe theoretical maximum value, so the control circuit will turn off thepower tube in advance. Even though there are still existed some chancesthat power tube having upper limited current or transformer saturation,however, the time is limited and the safety of the power tube andtransformer could be guaranteed.

Another method is to enable S5 once, I4=Ia (Ic)*1.2; In the succeedingPWM cycle, if the S5 is not enabled, I4=Ia(Ic)*0.8, afterwards, the S5is disabled. It is noted that above multiple constant 1.2 and 0.8 couldbe bigger than 1 or less than 1, the exact value should be referenced bythe instantaneous response of the switch power supply. This method couldfurther improve the protection for the power tube and transformer so asto increase the maximum current output. What is more, S5 could beembodied as a digital processing logic to deal with the overloaded I4.To achieve a better monitoring effect, S5 is optimized to output anoverloading monitoring signal.

As shown in FIG. 1, FIG. 2 and FIG. 3, the single ended continuouscurrent mode is embodied, as a result, PCL, PCLs, PCL2 and S5 areimplemented with time delay circuit for preventing a pinnacle from beingstarted which could accidentally turn off or enable S5.

It is worth to mention that above overloading and saturationpreventative switch power supply PWM control techniques are also appliedin push-pull, half-bridge, and full-bridge structure. If the primarycurrent of the power tube and transformer is checked over upper limit bythe overloading and saturation preventative circuit, then the errorsignal will be forcedly adjusted (for example, adding force adjustingpin3 and pin4 level to S3, S5), so that in the next or subsequent PWMcycle, the duty cycle ration will be fall down, and the peak current ofthe power tube and transform-primary will be reduced as well, as aresult, the power tube and the transformer are well protected thussignificantly improving the security and reliability of the switch powersupply.

In other words, a single ended PWM control circuit which adopted aneconomical switch power triode, comprises an input and outputrespectively coupled with the base and emitter of the triode, whereinthe base of the power tube includes a high voltage, highly resistantresistance connected with the high voltage source or collector of thepower tube (via the transformer-primary to coupled with high voltagesource). Under the enabling state, the high voltage, highly resistantresistance (output being controllable), which is coupled with the base,is adapted for providing the power tube a base micro-current, and thecurrent of the emitter of the power tube will charge the IC power supplyfilter capacitor through the diode so as to accomplish the starting upprocess. Under the normal state, PWM is in positive period, one pathenables the power tube to be positive biased, while another path dropsdown the emitter of the power tube, then the power tube is conductible;if the PWM is in negative period, one path drops down the base of thepower tube. Due to the fact of the memory effect, the power tube willnot be cut off immediately, the emitter of the power tube could be flywheeled by the diode, or the emitter of the power tube could be droppeddown to delay the time until the power tube is cut off, or until theemitter of the power tube being clamped. It is noted that after thepower tube is cut off, the base of the power tube is negative biased sothat the voltage withstanding of the collector of the power tube havebeen significantly improved.

Referring to the FIG. 4, FIG. 5 and FIG. 6, the independent PFC areillustrated wherein IC are circumscribed within the dash line. R3 isadapted for checking PFC induction Lp current, and the PFC current (Lpcurrent) reference output filter capacitor Cir and high power tube Qpcould be resided outside or integrated within the IC. UD is commercialpower rectifier synchronous input and RV is high voltage, highresistible resistance. Rh, R1 are PFC output voltage signal samplecircuit, which is adapted for filtering the high frequency voice ofthousands Hz. VA is adapted for checking the voltage signal, having aquad-voltage comparator for outputting a first high voltage Vhh, asecond high voltage Vh, a first low voltage Vl and a second low voltageVll signal, or an Analog/Digital converter. IR1 is a present PFC currentreference output register; IR2 is PFC current reference output register;IR3 is major cycle PFC average current reference output register; II ispresent PFC current reference output register (IR1) major cycleaccumulator; CT is a major cycle counter; IR0, IR1, IR2, and IR3(according to the accuracy) are preferably located at the pin number 8and pin number 9, while the CT is preferably located at pin number 12,and II is preferably located at pin number 20 and 21. it is noted thatthe major cycle CT should be larger than commercial cycle.

As shown in FIG. 4, PFC current reference generating logic, i.e. adigital processing unit, is adapted to delay time to an extent afterpower on reset. PFC logic sets a permissive signal to achieve the PFCsoft enablement, and at the same time, set the IR2 and IR3 as the halfvalue of its maximum value, and II and CT reset; after a major cycle isaccomplished, a major cycle current reference output average valueobtained from the II will be feed in the IR3, and then a new major cycleis re-enabled; voltage detecting 0000 (i.e. Vhh=0, Vh=0, Vl=0, Vll=0),IR1 is set to be the maximum value (stf), so as to prevent PFCoutputting voltage falling down too much; voltage detection 1111, IR1 isset to 0 (c10), PFC logic is set prohibitive signal so as to preventoutput voltage from being excess the upper limit, after the voltagedetection is resumed to 0011, PFC logic sets a permissive signal;voltage detection non-0000 and non-1111, and PFC logic is set to bepermissive, IR2 is sub-classed into IR1; voltage detection from 0000 to0001, then 0011, IR2 is downwardly adjusted to search the real IR2value; voltage detection from 0011 to 0001 and then 0011, IR2 downwardlyadjusted; for those stable load, IR2 is downwardly or upwardly adjusted,minus one or add one could be applicable; for those load with a widerange, an adjustable equivalent register is embodied, and if IR2 needsto be continuously adjusted, the adjustable equivalent register will beincreased or decreased accordingly. Therefore, there exists a necessityto enable a limited method for ensuring IR2 bigger than a set value, soas to guarantee PFC working in a continuous manner.

As shown in FIG. 5, PFC current reference generating logic (IR1 logic)is illustrated. it is quite similar with above mentioned IR logic,wherein the difference is that alternation of the IR2 is synchronouslymatting with the movement of UD (namely, UD sync or commercial sync);voltage detection 0000, to 0001, to 1111 to 0111, and UD sync issub-classed into the IR2; voltage detection 0111, and UD sync IR2downwardly adjusted; voltage detection 0001, UD sync IR2 upwardlyadjusted; voltage detection 0011 non-enabled, so that Vh and Vl could becombined into a same signal, only 0000, 0001, 0111, and 1111 are leftpossible. However, if the two signals are not combined, the alternatingfrequency will be reduced; as a result, during the half cycle ofcommercial power, PFC current reference is constant.

As shown in FIG. 6, PFC current reference generating logic (IR2 logic),should be delay to an extent after the power on reset, and PFC logicpermissive signal is set so as to strengthening the PFC softerenablement; voltage detection 1111, PFC logic set a prohibitive signal;UD sync voltage detecting 0111, PFC current reference is set Ri1; UDsync voltage detection 0111, PFC current reference is set Ri2; UD syncvoltage detection 0001, PFC current reference is set Ri3; UD syncvoltage detection 0000, PFC current reference is set Ri4; currentreferences Ri1, Ri2, Ri3, Ri4 are arranged in a gradually increasedmanner, for example, 25%, 50%, 75%, 100%; or 40%, 60%, 80%, and 100%; Inresponse to different version, VA should be correspondingly adjusted,namely, this difference could be deemed as D/A conversion. As a result,D/A conversion could be designed to four digits and IR2 logic could bedesigned to more complicated. What is more, PFC current reference valuecould be accurately calculated based on the voltage detection. It isnoted that the variation of PFC current reference should besynchronously mated with UD.

The logic unit generated from PFC current reference shown in FIG. 4,FIG. 5 and FIG. 6 could directly replace the error amplifier of UC3854IC and the like, therefore providing a safer and superb continuouscurrent mode control IC; likewise, the logic units could replace theerror amplifier of UC 3852 and the like, so as to form a safer andreliable non-continuous current mode, constant conductible time controlIC.

PFC shown in the FIG. 4, FIG. 5, and FIG. 6 could be embodied as averagecurrent mode, which is working under CCM or DCM (for DCM, R3 detectedPFC current should be filtered first to be send to −4 amplifier); −4 isPFC current amplifier, and the output of the PFC current amplifier issend to the timing circuit; link is a proportion current circuit,comprises three triodes or MOS tubes, one for current reference input,the other two for proportional output. The timing circuit comprises twoproportioning capacitors, (shown as 30 PF and 15 PF, being eitherdisposed within or outside the IC. Here, the two proportioningcapacitors are shorten as Ct2 and Ct1), two triodes or MOS tubes Ta andTb adapted for discharging the proportioning capacitors, and twoamplifiers Aa and Ab for monitoring the voltages of the twoproportioning capacitors, wherein a pair of digital signal arerespectively feed into Ta and Th, and then Aa and Ab will output a pairof digital signals. PFC reference outputting circuit outputs a currentreference via Cir, Ri, a stabilized current generated from lmk willcharge two capacitors having a 2:1 capacity ratio; the mechanism of thePFC logic (pulse width adjustable logic circuit) is to workingsynchronously with oscillator, but is under control of the PFC logicpermissive signal; if the oscillator is on rising edge, and then PFCenter a cut-off period, that is to say, the PFC power tube Qp is off,and PFC induction Lp current decreased, Ct2 discharging tube Ta is offand stabilizedly discharging, Ct1 discharging tube Tb is kept on and CT1voltage is kept 0; when the current represented by the Ct2 voltage reachthe same level of the PFC induction voltage, i.e. the comparator Ab ison rising edge, Ct1 discharging tube Th is turned off and stabilizedlycharging; when the Ct1 voltage catches up the Ct2 voltage, that is tosay, the comparator Ab is on the rising edge, the PFC enters into anenablement period, PFC power tube Qp is enabled, PFC induction Lpcurrent increased, Ct2 discharging tube Ta and Ct1 discharging tube Tbare enabled, Ct1 and Ct2 are discharged to be 0 voltage until the risingedge of the next oscillator is close and a new PFC cycle is initiated;It is proven that the controlling method according to the presentinvention, under a continuous current mode and R3 detection is free offiltration, PFC is a desirable average current mode, and moreimportantly, when Aa is on the rising edge, Lp current is averagecurrent.

VA voltage signal detection shown in the FIG. 4, FIG. 5 and FIG. 6,could apply A/D converter for outputting voltage value. So, PFC currentreference ultimately could be converted into a D/A converter. However,the PFC current reference generating logic should be compliable with thefollowing rules: VA input is non-filterable and high frequency voicefree; preferably, Vhh logic is applicable, when vhh=1, PFC will preventthe PFC output voltage from being excess the upper limit; andpreferably, Vll logic is applicable, when Vll=0, PFC sets a high or amaximum reference value, so as to prevent PFC outputting voltage fromfalling too much and to simplify the monitoring process, and preferably,Vll monitoring signal could be outputted. Even though Vhh and Vll isoptional, but the Vhh and Vll PFC is safer and more reliable. When Vhh=1and Vll=0 are not guaranteed, PFC could maintain PFC current referencebeing constant during a major cycle. In other words, when a major cycleis on or off, the current reference is adjusted. Furthermore, the majorcycle should be synchronously mating with the edges of half cycle'sinteger multiple or far above the commercial power's half cycle.According to the A/D of VA input and D/A conversion's complication, amore accurate PFC current reference logic sounds more reliable. As aresult, the PFC techniques according to the present invention could beembodied as single processing unit having digital processing logic.

Accordingly, the digital processing PFC control circuit of the presentinvention has a desirable power factor and an ideal total harmonicdistortion, and is deemed as a high quality PFC control circuit.

Referring to FIG. 7, FIG. 8, and FIG. 9, a digital processing and highquality PFC green switch power supply for prevent overload andsaturation is illustrated. The monolithic green switch power supply ICis applied according to the present invention, the standby erroramplifier and the main error amplifier are applied as TL431, and thereare standby isolation circuit and main isolation circuit. It is notedthat—Pm remote control signal, in response to the main error signal, isbeing send to the main control circuit, a triode is applied by theremote control circuit as a switch for directly controlling the workingpower of the main feedback circuit. As shown in the Figs, threepreferred green switche power supply ICs are resided with the dash line.For a better monitoring effect, a standby power supply overloadmonitoring signal, a main power supply overload monitoring signal, a PFCVll monitoring signal, and preferably, a combined monitoring signalcould be outputted from the IC. In case of PFC is non applicable, tworemaining two switch power supply ICs are still in function. The abovementioned IC, main power supply, standby power supply, and PFC devicecould share an integrated oscillator or an oscillator disposed with anoutside timing element.

Referring to FIG. 10, FIG. 11, and FIG. 12, a PC standard (ATX, ATX12,SSI) green switch PC power supply with overload and saturationpreventative function and digital processing PFC design are illustrated.The monolithic green switch power supply IC is applied according to thepresent invention, the standby error amplifier and the main erroramplifier are applied as TL431, and there are standby isolation circuitand main isolation circuit. It is noted that—PS-on remote controlsignal, in response to the main error signal, is being send to the maincontrol circuit, a triode is applied by the remote control circuit as aswitch for directly controlling the working power of the main feedbackcircuit. The standby power supply is single ended, and the excitingcurrent is adapted for discharging to main output through diode Dfb.

FIG. 13 and FIG. 14 show showing a single ended hybrid switch powersupply, wherein the output power from Uo2 should be bigger than Uo1.

One skilled in the art will understand that the embodiment of thepresent invention as shown in the drawings and described above isexemplary only and not intended to be limiting.

It will thus be seen that the objects of the present invention have beenfully and effectively accomplished. It embodiments have been shown anddescribed for the purposes of illustrating the functional and structuralprinciples of the present invention and is subject to change withoutdeparture form such principles. Therefore, this invention includes allmodifications encompassed within the spirit and scope of the followingclaims.

1. A green switch-mode power supply with standby function, comprising: astandby switched-mode power supply, comprising a standby convertercircuit, a standby feedback circuit, and a standby control circuit; anda main switched-mode power supply, comprising a main converter circuit,a main feedback circuit, and a main control circuit, wherein said mainswitched-mode power supply is subjected to a remote control signal to beon/off, wherein said main feedback circuit comprises a main samplingcircuit, a main error amplifier, a main isolation circuit, and a remotecontrol circuit, wherein said main control circuit comprises a mainpulse adjustable circuit, a main driven circuit and a main switched-modepower supply prohibitive circuit; and a supplemental circuit, comprisingan initiating circuit, a rectifying filter circuit, wherein DC terminalof said standby switched-mode power supply, said standby controlcircuit, DC input terminal of said main switch-mode power supply andsaid main control circuit are common grounded; and a monolithic greenswitched-mode power supply IC integrated with said standby controlcircuit, said main control circuit and said initiating circuit of saidsupplemental circuit, wherein said monolithic green switched-mode powersupply IC is activated by said initiating circuit and is power-suppliedby said standby switch-mode power supply, wherein said remote controlsignal is sent to said main control circuit in response to a main errorsignal for controlling said main switch-mode power supply on/off,wherein when said remote control signal is an “off” signal, said remotecontrol circuit force said main error signal being less than apredetermined threshold value, when said remote control signal is an“on” signal, said remote control circuit is deactivated, such that saidmain sampling circuit outputs a voltage signal to said main erroramplifier to generate an optically coupled current through said mainisolation circuit so as to output a main error signal; wherein said mainerror signal is monitored by said main switched-mode power supplyprohibitive circuit, when said main error signal is smaller than saidthreshold value, said remote control signal is assumed to be said “off”signal, such that said switched-mode power supply prohibitive circuitforces said main driven circuit to output a low electric level so as toswitch off said main switch-mode power supply, and when said main errorsignal is not smaller than said threshold value, said remote controlsignal is assumed to be said “on” signal, that said main pulseadjustable circuit generates a main pulse in responsive to said mainerror signal, such that said main driven circuit is normally operatingto switch on said main switch-mode power supply.
 2. The greenswitch-mode power supply with standby function, as recited in claim 1,wherein an optical coupling is applied in said remote control circuitfor sending said remote control signal to said main control circuit,wherein when said remote control signal is an “off” signal, said mainswitched-mode power supply prohibitive circuit forces said main drivencircuit to output a low electric level so as to switch off said mainswitch-mode power supply, and when said remote control signal is an “on”signal, said main pulse adjustable circuit generates a main pulse inresponsive to said main error signal, such that main driven circuit isnormally operating to switch on said main switch-mode power supply. 3.The green switch-mode power supply IC with standby function, as recitedin claim 2, wherein said standby control circuit further comprises astandby pulse adjustable circuit and a standby driven circuit, saidstandby pulse adjustable circuit generating a standby pulse signal inresponse to a standby error signal, wherein said main control circuitfurther comprises said main pulse adjustable circuit, said main drivencircuit and said main switch-mode power supply prohibitive circuit;wherein said remote control signal is sent to said main switched-modepower supply prohibitive circuit, when said remote control signal is an“off” signal, said main switched-mode power supply prohibitive circuitforces said main driven circuit to output a low electric level so as toswitch off said main switch-mode power supply, and when said remotecontrol signal is an “on” signal, said main pulse adjustable circuitgenerates a main pulse in responsive to said main error signal, suchthat main driven circuit is normally operating to switch on said mainswitch-mode power supply.
 4. The green switch-mode power supply IC withstandby function, as recited in claim 2, wherein said IC is furtherintegrated with a PFC error amplifier and a PFC control circuit, whereinsaid PFC control circuit comprises a PFC pulse adjustable circuit and aPFC driven circuit.
 5. The green switch-mode power supply IC withstandby function, as recited in claim 3, wherein said IC is furtherintegrated with a PFC error amplifier and a PFC control circuit, whereinsaid PFC control circuit comprises a PFC pulse adjustable circuit and aPFC driven circuit.